Oracle OLAP Hierarchical Tools
Oracle Database Tips by Donald Burleson
Hierarchy Handling Improvements
Enhancements include additional support for two primary
clients, BI Beans and JOLAP, in terms of:
Hierarchical Sorting - The improved API
allows the client to specify explicitly that a source be
sorted hierarchically. This enhancement allows the client to
specify a specific sort order within each level and to specify
whether parents come first or last.
Multi-hierarchy Selections - The client can
create dimension selections that contain members from multiple
hierarchies. This is a requirement of BI Beans.
Hierarchically Aware Dimension Values - The
ID of the hierarchy and level encoded in the values of a
dimension member is a requirement for multi-hierarchical
selections to work. It allows the application developer to
write more efficient SQL queries.
Metadata Changes - The MDM (multi-dimensional
model) client metadata model has been enhanced to provide
objects that represent the notion of a shared level. This is a
With Oracle Database 10g, Client has better control
over the usage and selection of a hierarchy. Given a selection
from a hierarchy and a self-relation representing the parent
of each member of the hierarchy, the client is able to sort
the selection hierarchically with either the parent or the
children first. Also, the client can now specify a sort order
for siblings by either attribute or measure values.
10g, it becomes possible to replace the hierarchy
class with explicit subclasses. MdmLevelHierarchy represents
hierarchies that are based on levels. MdmLevelHierarchy
contains a list of levels, a ?level attribute?, and a ?level
order to support multi-hierarchy selections in Oracle Database
10g, some changes are introduced in the metadata.
Now, the dimension itself dimensions parent attributes. Each
hierarchy returns the same instance of MdmAttribute to the
call getParentAttribute, and similarly for getLevelAttribute
10g, all dimensions obtained from the getDimensions methods on
MdmSchema and MdmMeasure are instances of MdmPrimaryDimension.
An MdmPrimaryDimension is a new class used to represent top
level, logical dimensions like ?Products,? ?Geographies,? and
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